This invention relates to the field of digital logic circuits. More specifically, the present invention is a high-performance flip-flop circuit, especially useful in the design of high-performance electronic circuits.
A digital system is made up of logic elements including AND gates, OR gates, NAND gates, NOR gates, inverters, flip-flops, multiplexers, and many others. These basic logic elements are combined and used to create larger, more complex logic functions such as registers, shifters, accumulators, state machines, processing units, and microprocessors, to name a few. These functions may be embodied on integrated circuits, printed circuit boards, and other similar techniques. Ultimately, these logic elements are used to create digital systems, which may contain millions of logic elements, or even more. Some examples of digital systems are computers, automated teller machines, modems, network servers, telecommunications systems, global positioning systems, satellite controllers, automotive controllers, industrial automation controllers, embedded controllers, laser printer controllers, and application-specific hardware.
Rapidly advancing technology allows the creation of more complex, higher functionality, and higher performance digital systems. Although existing digital systems have generally met with substantial success, improvements are continually needed to address the limitations of the present technology, and to provide even greater functionality. Improvements in process technology for integrated circuits allow greater numbers of logic elements to be placed on a single chip. Improvement in the logic elements themselves and accompanying layout also saves valuable silicon area, which increases the logic density. For example, reducing the number of logic elements needed to implement a logical function leads to an increase in the number of functions an electronic circuit can provide. Furthermore, digital systems need to provide increasingly higher performance. Since logic elements form the critical path for digital systems, higher performance logic elements can directly improve the overall performance of the system. For example, a microprocessor may contain more than 50,000 flip-flops; improving the performance of a basic flip-flop will generally greatly improve the overall performance of the processor. In addition to providing greater functionality and better performance, the logic elements must also provide reliability and low power consumption.